The invention relates generally to the field of fluid filling. More particularly, the invention concerns an apparatus and method for filling a pouch with a fluid material in a manner that the pouch is degassed and receives a precise amount of the fluid material during the filling process.
Commercial cartridges containing a pouch for receiving a fluid material, such as large ink jet cartridges (1000 ml or greater), are required for commercial, wide format ink jet printers. Typically, these cartridges consist of two-molded plastic cartridge halves generally ultrasonically sealed together. The cartridge also contains a pouch to be filled arranged in the interior portion of the cartridge. An opening is generally provided in a portion of the cartridge to provide access to the pouch as well as to means of inserting and removing the pouch from the cartridge. Further, a septum for filling the pouch is typically arranged in the top portion of the pouch. This septum is similar to devices used on pharmaceutical vials. Filling the pouch with a fluid material, such as ink, is generally undertaken after the cartridge has been assembled, by inserting a needle through the septum and pumping ink through the needle. Heretofore, it has generally been problematic to deliver a precise weight of fluid material into the pouch.
Another problem with current fluid filling developments is that the pouch or container being filled generally will contain a fair amount of residual gasses that negatively influence the outcome of the filling process. Those skilled in the art will appreciate that some printers, like ink jet printers having an electric print head rather than a thermal print head such as found in most desktop ink jet printers, require a more precise pouch loading precondition. Because of this, all gases must be evacuated from the pouch to be filled. An acceptable level of oxygen remaining in the cartridge is less than 1 part per million.
Therefore, there persists a need in the art for an apparatus and method for accurately and precisely filling and degassing a sealed pouch contained in a cartridge that is cost effective to manufacture, simple to use, and is reliable.
The present invention is directed to overcoming one or more of the problems set forth above Briefly summarized, according to one aspect of the present invention, a method of filling and degassing a pouch contained in a cartridge comprises providing a cartridge containing a pouch to be filled and degassed. A fluid injection unit is provided having a fluid injection member, a support member for holding said cartridge, means for determining the weight of pouch. Means is provided for pivoting cartridge from a substantially horizontal position to a substantially vertical position to effectuate loading and degassing. After degassing the pouch, the cartridge is mounted onto the support member of the fluid injection unit in a substantially horizontal position so that fluid injection member is alignably inserted into the pouch to be filled. The cartridge is pivoted from a substantially horizontal position to a substantially vertical position thereby repositioning the pouch in a substantially vertical position. The weight of the cartridge and pouch is determined in the vertical position prior to injecting fluid into the pouch. Once the cartridge and pouch are weighed, the cartridge is rotated from the substantially vertical position to the substantially horizontal position thereby repositioning the pouch in a substantially horizontal position for liquid injection. The fluid is then introduced into the pouch to a level that exceeds a predetermined level forming an at least partially filled pouch. Again the cartridge containing a partially filled pouch is rotated from the substantially horizontal position to the substantially vertical position. The weight of the at least partially filled pouch is then determined. Any excess fluid and entrapped air is then evacuated from the partially filled pouch. Finally, the cartridge containing the precisely loaded pouch is then rotated from the substantially vertical position to the substantially horizontal position for removal from the fixture.
The present invention has numerous advantages over prior developments. In particular, the present invention provides for removal of all entrapped air from the pouch to be filled, preventing degradation of the ink. Further, the present invention provides very accurate filling of the pouch to be filled. Moreover, handling of the cartridge/pouch is minimized using the present invention. Once the cartridge/pouch is inserted into the fixture, the entire filling/degassing operation takes place automatically. This also minimizes the number of times the septum is pierced during the manufacturing process. Still further, the throughput of the filling/degassing operation of the present invention is maximized. Also, the design of the mechanism is such that multiple cartridge/pouches can be filled/degassed simultaneously. Finally, the process can be applied to any product where accurate filling of a pouch with a liquid and removal of the air is required.